Setting ssh_private_key_file fails with linode error

[pingiun]

Overview of the Issue

I tried to set the ssh_private_key_file to make sure I can use the same SSH key after setting up a Linode with NixOS. First I tried using https://www.packer.io/docs/datasources/sshkey, then I tried using my own private key but they both fail.

Build 'linode.example' errored after 838 milliseconds 558 microseconds: Error creating Linode: [400] [authorized_keys] SSH Key 1 key-type must be ssh-dss, ssh-rsa, ecdsa-sha2-nistp, or ssh-ed25519.

Reproduction Steps

Use the linode example config, this still works:

locals { timestamp = regex_replace(timestamp(), "[- TZ:]", "") }

source "linode" "example" {
  image             = "linode/debian9"
  image_description = "My Private Image"
  image_label       = "private-image-${local.timestamp}"
  instance_label    = "temporary-linode-${local.timestamp}"
  instance_type     = "g6-nanode-1"
  linode_token      = "YOUR API TOKEN"
  region            = "us-east"
  ssh_username      = "root"
}

build {
  sources = ["source.linode.example"]
}

Now add any private key using the ssh_private_key_file option, as stated in the docs. Provisioning now fails.

Plugin and Packer version

Packer v1.7.3

packer-plugin-linode_v1.0.0_x5.0_darwin_amd64

Simplified Packer Buildfile

Reproducable build file

packer {
  required_plugins {
    linode = {
      version = ">= 0.0.1"
      source  = "github.com/hashicorp/linode"
    }
    sshkey = {
      version = ">= 0.1.0"
      source  = "github.com/ivoronin/sshkey"
    }
  }
}

locals { timestamp = regex_replace(timestamp(), "[- TZ:]", "") }


variable "linode_token" {
  type      = string
  sensitive = true
}

source "linode" "example" {
  image                = "linode/debian9"
  image_description    = "NixOS"
  image_label          = "nixos-${local.timestamp}"
  instance_label       = "packer-build-${local.timestamp}"
  instance_type        = "g6-standard-2"
  linode_token         = var.linode_token
  region               = "us-east"
  ssh_username         = "root"
  ssh_private_key_file = data.sshkey.install.private_key_path
}

data "sshkey" "install" {}

build {
  sources = ["source.linode.example"]
}

Operating system and Environment details

running from MacOS (but via nix), trying to install NixOS with NIXOS_LUSTRATE on a debian 9 base.

Log Fragments and crash.log files

Full logs

2021/07/20 18:03:20 [INFO] Packer version: 1.7.3 [go1.16.6 darwin amd64]
2021/07/20 18:03:20 [TRACE] discovering plugins in /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin
2021/07/20 18:03:20 [TRACE] discovering plugins in /Users/jelle/.packer.d/plugins
2021/07/20 18:03:20 [TRACE] discovering plugins in .
2021/07/20 18:03:20 [INFO] PACKER_CONFIG env var not set; checking the default config file path
2021/07/20 18:03:20 [INFO] PACKER_CONFIG env var set; attempting to open config file: /Users/jelle/.packerconfig
2021/07/20 18:03:20 [WARN] Config file doesn't exist: /Users/jelle/.packerconfig
2021/07/20 18:03:20 [INFO] Setting cache directory: /Users/jelle/dev/projects/peertube-saas/nixos-packer/packer_cache
2021/07/20 18:03:20 [TRACE] init: plugingetter.ListInstallationsOptions{FromFolders:[]string{"/nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer", ".", "/Users/jelle/.packer.d/plugins"}, BinaryInstallationOptions:plugingetter.BinaryInstallationOptions{APIVersionMajor:"5", APIVersionMinor:"0", OS:"darwin", ARCH:"amd64", Ext:"", Checksummers:[]plugingetter.Checksummer{plugingetter.Checksummer{Type:"sha256", Hash:(*sha256.digest)(0xc000086480)}}}}
2021/07/20 18:03:20 [TRACE] listing potential installations for "github.com/hashicorp/linode" that match ">= 0.0.1". plugingetter.ListInstallationsOptions{FromFolders:[]string{"/nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer", ".", "/Users/jelle/.packer.d/plugins"}, BinaryInstallationOptions:plugingetter.BinaryInstallationOptions{APIVersionMajor:"5", APIVersionMinor:"0", OS:"darwin", ARCH:"amd64", Ext:"", Checksummers:[]plugingetter.Checksummer{plugingetter.Checksummer{Type:"sha256", Hash:(*sha256.digest)(0xc000086480)}}}}
2021/07/20 18:03:20 [TRACE] for plugin github.com/hashicorp/linode found 1 matching installation(s)
2021/07/20 18:03:20 [TRACE] listing potential installations for "github.com/ivoronin/sshkey" that match ">= 0.1.0". plugingetter.ListInstallationsOptions{FromFolders:[]string{"/nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer", ".", "/Users/jelle/.packer.d/plugins"}, BinaryInstallationOptions:plugingetter.BinaryInstallationOptions{APIVersionMajor:"5", APIVersionMinor:"0", OS:"darwin", ARCH:"amd64", Ext:"", Checksummers:[]plugingetter.Checksummer{plugingetter.Checksummer{Type:"sha256", Hash:(*sha256.digest)(0xc000086480)}}}}
2021/07/20 18:03:20 [TRACE] for plugin github.com/ivoronin/sshkey found 1 matching installation(s)
2021/07/20 18:03:20 [INFO] (telemetry) Finalizing.
2021/07/20 18:03:20 waiting for all plugin processes to complete...
2021/07/20 18:03:21 [INFO] Packer version: 1.7.3 [go1.16.6 darwin amd64]
2021/07/20 18:03:21 [TRACE] discovering plugins in /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin
2021/07/20 18:03:21 [TRACE] discovering plugins in /Users/jelle/.packer.d/plugins
2021/07/20 18:03:21 [TRACE] discovering plugins in .
2021/07/20 18:03:21 [INFO] PACKER_CONFIG env var not set; checking the default config file path
2021/07/20 18:03:21 [INFO] PACKER_CONFIG env var set; attempting to open config file: /Users/jelle/.packerconfig
2021/07/20 18:03:21 [WARN] Config file doesn't exist: /Users/jelle/.packerconfig
2021/07/20 18:03:21 [INFO] Setting cache directory: /Users/jelle/.cache/packer
2021/07/20 18:03:21 [TRACE] listing potential installations for "github.com/hashicorp/linode" that match ">= 0.0.1". plugingetter.ListInstallationsOptions{FromFolders:[]string{"/nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer", ".", "/Users/jelle/.packer.d/plugins"}, BinaryInstallationOptions:plugingetter.BinaryInstallationOptions{APIVersionMajor:"5", APIVersionMinor:"0", OS:"darwin", ARCH:"amd64", Ext:"", Checksummers:[]plugingetter.Checksummer{plugingetter.Checksummer{Type:"sha256", Hash:(*sha256.digest)(0xc000086600)}}}}
2021/07/20 18:03:21 [TRACE] Found the following "github.com/hashicorp/linode" installations: [{/Users/jelle/.packer.d/plugins/github.com/hashicorp/linode/packer-plugin-linode_v1.0.0_x5.0_darwin_amd64 v1.0.0}]
2021/07/20 18:03:21 [INFO] found external [-packer-default-plugin-name-] builders from linode plugin
2021/07/20 18:03:21 [TRACE] listing potential installations for "github.com/ivoronin/sshkey" that match ">= 0.1.0". plugingetter.ListInstallationsOptions{FromFolders:[]string{"/nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer", ".", "/Users/jelle/.packer.d/plugins"}, BinaryInstallationOptions:plugingetter.BinaryInstallationOptions{APIVersionMajor:"5", APIVersionMinor:"0", OS:"darwin", ARCH:"amd64", Ext:"", Checksummers:[]plugingetter.Checksummer{plugingetter.Checksummer{Type:"sha256", Hash:(*sha256.digest)(0xc000086600)}}}}
2021/07/20 18:03:21 [TRACE] Found the following "github.com/ivoronin/sshkey" installations: [{/Users/jelle/.packer.d/plugins/github.com/ivoronin/sshkey/packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64 v0.1.0}]
2021/07/20 18:03:21 found external [-packer-default-plugin-name-] datasource from sshkey plugin
2021/07/20 18:03:21 [TRACE] validateValue: not active for linode_token, so skipping
2021/07/20 18:03:21 [TRACE] validateValue: not active for nixos_version, so skipping
2021/07/20 18:03:21 [TRACE] Starting external plugin /Users/jelle/.packer.d/plugins/github.com/ivoronin/sshkey/packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64 start datasource -packer-default-plugin-name-
2021/07/20 18:03:21 Starting plugin: /Users/jelle/.packer.d/plugins/github.com/ivoronin/sshkey/packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64 []string{"/Users/jelle/.packer.d/plugins/github.com/ivoronin/sshkey/packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64", "start", "datasource", "-packer-default-plugin-name-"}
2021/07/20 18:03:21 Waiting for RPC address for: /Users/jelle/.packer.d/plugins/github.com/ivoronin/sshkey/packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64
2021/07/20 18:03:21 packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64 plugin: 2021/07/20 18:03:21 Plugin address: unix /tmp/packer-plugin602722078
2021/07/20 18:03:21 packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64 plugin: 2021/07/20 18:03:21 Waiting for connection...
2021/07/20 18:03:21 Received unix RPC address for /Users/jelle/.packer.d/plugins/github.com/ivoronin/sshkey/packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64: addr is /tmp/packer-plugin602722078
2021/07/20 18:03:21 packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64 plugin: 2021/07/20 18:03:21 Serving a plugin connection...
2021/07/20 18:03:21 packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64 plugin: 2021/07/20 18:03:21 [TRACE] starting datasource -packer-default-plugin-name-
2021/07/20 18:03:21 [TRACE] Starting external plugin /Users/jelle/.packer.d/plugins/github.com/hashicorp/linode/packer-plugin-linode_v1.0.0_x5.0_darwin_amd64 start builder -packer-default-plugin-name-
2021/07/20 18:03:21 Starting plugin: /Users/jelle/.packer.d/plugins/github.com/hashicorp/linode/packer-plugin-linode_v1.0.0_x5.0_darwin_amd64 []string{"/Users/jelle/.packer.d/plugins/github.com/hashicorp/linode/packer-plugin-linode_v1.0.0_x5.0_darwin_amd64", "start", "builder", "-packer-default-plugin-name-"}
2021/07/20 18:03:21 Waiting for RPC address for: /Users/jelle/.packer.d/plugins/github.com/hashicorp/linode/packer-plugin-linode_v1.0.0_x5.0_darwin_amd64
2021/07/20 18:03:21 packer-plugin-linode_v1.0.0_x5.0_darwin_amd64 plugin: 2021/07/20 18:03:21 Plugin address: unix /tmp/packer-plugin264359411
2021/07/20 18:03:21 Received unix RPC address for /Users/jelle/.packer.d/plugins/github.com/hashicorp/linode/packer-plugin-linode_v1.0.0_x5.0_darwin_amd64: addr is /tmp/packer-plugin264359411
2021/07/20 18:03:21 packer-plugin-linode_v1.0.0_x5.0_darwin_amd64 plugin: 2021/07/20 18:03:21 Waiting for connection...
2021/07/20 18:03:21 packer-plugin-linode_v1.0.0_x5.0_darwin_amd64 plugin: 2021/07/20 18:03:21 Serving a plugin connection...
2021/07/20 18:03:21 packer-plugin-linode_v1.0.0_x5.0_darwin_amd64 plugin: 2021/07/20 18:03:21 [TRACE] starting builder -packer-default-plugin-name-
2021/07/20 18:03:21 [TRACE] Starting internal plugin packer-provisioner-file
2021/07/20 18:03:21 Starting plugin: /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer []string{"/nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer", "plugin", "packer-provisioner-file"}
2021/07/20 18:03:21 Waiting for RPC address for: /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer
2021/07/20 18:03:21 packer-provisioner-file plugin: [INFO] Packer version: 1.7.3 [go1.16.6 darwin amd64]
2021/07/20 18:03:21 packer-provisioner-file plugin: [INFO] PACKER_CONFIG env var not set; checking the default config file path
2021/07/20 18:03:21 packer-provisioner-file plugin: [INFO] PACKER_CONFIG env var set; attempting to open config file: /Users/jelle/.packerconfig
2021/07/20 18:03:21 packer-provisioner-file plugin: [WARN] Config file doesn't exist: /Users/jelle/.packerconfig
2021/07/20 18:03:21 packer-provisioner-file plugin: [INFO] Setting cache directory: /Users/jelle/.cache/packer
2021/07/20 18:03:21 packer-provisioner-file plugin: args: []string{"packer-provisioner-file"}
2021/07/20 18:03:21 Received unix RPC address for /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer: addr is /tmp/packer-plugin479551696
2021/07/20 18:03:21 packer-provisioner-file plugin: Plugin address: unix /tmp/packer-plugin479551696
2021/07/20 18:03:21 packer-provisioner-file plugin: Waiting for connection...
2021/07/20 18:03:21 packer-provisioner-file plugin: Serving a plugin connection...
2021/07/20 18:03:21 [TRACE] Starting internal plugin packer-provisioner-shell
2021/07/20 18:03:21 Starting plugin: /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer []string{"/nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer", "plugin", "packer-provisioner-shell"}
2021/07/20 18:03:21 Waiting for RPC address for: /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer
2021/07/20 18:03:22 packer-provisioner-shell plugin: [INFO] Packer version: 1.7.3 [go1.16.6 darwin amd64]
2021/07/20 18:03:22 packer-provisioner-shell plugin: [INFO] PACKER_CONFIG env var not set; checking the default config file path
2021/07/20 18:03:22 packer-provisioner-shell plugin: [INFO] PACKER_CONFIG env var set; attempting to open config file: /Users/jelle/.packerconfig
2021/07/20 18:03:22 packer-provisioner-shell plugin: [WARN] Config file doesn't exist: /Users/jelle/.packerconfig
2021/07/20 18:03:22 packer-provisioner-shell plugin: [INFO] Setting cache directory: /Users/jelle/.cache/packer
2021/07/20 18:03:22 packer-provisioner-shell plugin: args: []string{"packer-provisioner-shell"}
2021/07/20 18:03:22 Received unix RPC address for /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer: addr is /tmp/packer-plugin202666409
2021/07/20 18:03:22 packer-provisioner-shell plugin: Plugin address: unix /tmp/packer-plugin202666409
2021/07/20 18:03:22 packer-provisioner-shell plugin: Waiting for connection...
2021/07/20 18:03:22 packer-provisioner-shell plugin: Serving a plugin connection...
2021/07/20 18:03:22 [TRACE] Starting internal plugin packer-provisioner-shell
2021/07/20 18:03:22 Starting plugin: /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer []string{"/nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer", "plugin", "packer-provisioner-shell"}
2021/07/20 18:03:22 Waiting for RPC address for: /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer
2021/07/20 18:03:22 packer-provisioner-shell plugin: [INFO] Packer version: 1.7.3 [go1.16.6 darwin amd64]
2021/07/20 18:03:22 packer-provisioner-shell plugin: [INFO] PACKER_CONFIG env var not set; checking the default config file path
2021/07/20 18:03:22 packer-provisioner-shell plugin: [INFO] PACKER_CONFIG env var set; attempting to open config file: /Users/jelle/.packerconfig
2021/07/20 18:03:22 packer-provisioner-shell plugin: [WARN] Config file doesn't exist: /Users/jelle/.packerconfig
2021/07/20 18:03:22 packer-provisioner-shell plugin: [INFO] Setting cache directory: /Users/jelle/.cache/packer
2021/07/20 18:03:22 packer-provisioner-shell plugin: args: []string{"packer-provisioner-shell"}
2021/07/20 18:03:22 packer-provisioner-shell plugin: Plugin address: unix /tmp/packer-plugin507125290
2021/07/20 18:03:22 packer-provisioner-shell plugin: Waiting for connection...
2021/07/20 18:03:22 Received unix RPC address for /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer: addr is /tmp/packer-plugin507125290
2021/07/20 18:03:22 packer-provisioner-shell plugin: Serving a plugin connection...
2021/07/20 18:03:22 Build debug mode: false
2021/07/20 18:03:22 Force build: false
2021/07/20 18:03:22 On error:
linode.example: output will be in this color.

2021/07/20 18:03:22 Waiting on builds to complete...
2021/07/20 18:03:22 Starting build run: linode.example
2021/07/20 18:03:22 Running builder:
2021/07/20 18:03:22 [INFO] (telemetry) Starting builder
==> linode.example: Running builder ...
==> linode.example: Using existing SSH private key
==> linode.example: Creating Linode...
==> linode.example: Error creating Linode: [400] [authorized_keys] SSH Key 1 key-type must be ssh-dss, ssh-rsa, ecdsa-sha2-nistp, or ssh-ed25519.
2021/07/20 18:03:23 [INFO] (telemetry) ending
==> Wait completed after 840 milliseconds 984 microseconds
2021/07/20 18:03:23 machine readable: error-count []string{"1"}
Build 'linode.example' errored after 838 milliseconds 558 microseconds: Error creating Linode: [400] [authorized_keys] SSH Key 1 key-type must be ssh-dss, ssh-rsa, ecdsa-sha2-nistp, or ssh-ed25519.
==> Some builds didn't complete successfully and had errors:

2021/07/20 18:03:23 machine readable: linode.example,error []string{"Error creating Linode: [400] [authorized_keys] SSH Key 1 key-type must be ssh-dss, ssh-rsa, ecdsa-sha2-nistp, or ssh-ed25519."}
==> Builds finished but no artifacts were created.
==> Wait completed after 840 milliseconds 984 microseconds

==> Some builds didn't complete successfully and had errors:
--> linode.example: Error creating Linode: [400] [authorized_keys] SSH Key 1 key-type must be ssh-dss, ssh-rsa, ecdsa-sha2-nistp, or ssh-ed25519.

2021/07/20 18:03:23 [INFO] (telemetry) Finalizing.
==> Builds finished but no artifacts were created.
2021/07/20 18:03:23 waiting for all plugin processes to complete...
2021/07/20 18:03:23 /Users/jelle/.packer.d/plugins/github.com/ivoronin/sshkey/packer-plugin-sshkey_v0.1.0_x5.0_darwin_amd64: plugin process exited
2021/07/20 18:03:23 /Users/jelle/.packer.d/plugins/github.com/hashicorp/linode/packer-plugin-linode_v1.0.0_x5.0_darwin_amd64: plugin process exited
2021/07/20 18:03:23 /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer: plugin process exited
2021/07/20 18:03:23 /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer: plugin process exited
2021/07/20 18:03:23 /nix/store/qn5pnsn5dchqbsy20ajzjpaqqk9hwzlc-packer-1.7.3/bin/packer: plugin process exited

[LBGarber]

Hey there! Just wanted to give a few thoughts on this issue.

I noticed there is an unimplemented/undocumented root_ssh_key option which could be used to specify additional authorized_keys for an instance.

I'm not sure if this would be idiomatic (Packer isn't my area of expertise), but adding an authorized key option along the lines of

AuthorizedKeys []string `mapstructure:"authorized_keys"`

// step_create_linode.go

if pubKey := string(c.Comm.SSHPublicKey); pubKey != "" {
	createOpts.AuthorizedKeys = append(createOpts.AuthorizedKeys, pubKey)
}

createOpts.AuthorizedKeys = append(createOpts.AuthorizedKeys, authorizedKeys...)

could enable this functionality and closely mirror the Linode API.

Alternatively users could manually upload a public key at build time.

I'm not sure if either of these solutions would really solve the underlying issue, but I thought I'd throw them out there!